This invention relates to bearings between relatively moving elements, and particularly to slider bearings and to thrust and journal bearings between a shaft and bearing block.
Properly arranged grooves in slider, thrust and journal bearings are useful for increasing the load carrying capacity of the bearing structure, as by pumping the lubricant into the bearing against the influence of the load, which usually tends to squeeze the lubricant out. When the bearing is at rest, however, many lubricants tend to leak out of the bearing, urged by the bearing load, unopposed by pumping action. To counter this tendency, it has been proposed to use certain greases which are solids, in effect, and which remain as solids at the bearing entrance when it is stopped. Alternatively, it has been proposed to provide the entrance zone of the bearing with non-wetting surfaces to which lighter lubricants such as oil adhere with the result that the lubricant is retained in the bearing even at rest.
Another problem with grooved or pumping bearings, which problem is not solved by the use of grease or non-wetting surfaces, is that of entrainment of air into the bearing during operation, due to the combined effects of centrifugal force and the pumping action of the grooves. Such entrainment decreases the load-carrying capacity of the grease or oil in the bearing.
Now it has been discovered that the use of properly arranged magnetic lubricants in grooved bearings, together with magnetic retention means therefor, not only has the effect of preventing leakage of the lubricant when the bearing is stopped, but also has the more surprising effect of preventing entrainment of air into the bearing during operation.
Accordingly, it is an object of the invention to provide a bearing structure in which the load-carrying capacity of the lubricant is increased during operation without having leakage of the lubricant when the bearing is not operating; and
It is another object of the invention to provide a bearing structure as above described, and also having the effect of preventing entrainment of air into the bearing and lubricant during operation.